Peanut shelling grate



Patented July l, 1941 UNE serra Eli-'i FCE 3 Claims.

This invention relates to cast metal grates for use in machines for shelling peanuts and the like, and has for its chief object to improve the grate shown and claimed in Letters Patent No. 1,477,648.

'I'he shelling grate of said patent is composed of a plurality oi cast segments, each rectangular in shape land transversely arcuate to conform to, and form of, the curved Wall of a shelling chamber which has concentric therewith a rotor adapted to drive the nuts to be shelled in a whirl over said grates. There is cast on the inner face of the longitudinal ribs of each grate segment a series of spaced, raised, abrading shoulders, the function of which is to grind away the shells of the nuts whirling thereover until they become suiciently weakened to burst and free their kernels to escape unbroken through the grate openings. This novel abrading method was in marked distinction to the crushing method of other shellers and has been almost universally adopted by the industry, because its advantage of materially reducing breakage of the kernels more than compensated for its somewhat reduced output due to the longer time required to abrade the m shells than to crush them.

The chief objects of my present invention are to increase the capacity and abrading efi'ciency of such a grate by an improvement in the design of its working surface to the .end that while re- 'It taining ample strength in the casting and the capacity oi its patterns to be stripped from the sand molds, I nevertheless greatly increase the number of abrading shoulders, which are the eiective work elements, and at the same time increase the i? facility of the shelled kernels to escape unbroken by providing that they shall have the least possible contact with any non-abrasive surface area of the grate. The ideal operating conditions sought to be attained by the new design of grate is that the whirl of nuts shall have the maximum number of contacts with abrading shoulders in each circumferential travel and that the shelled kernels shall not roll over a plane surface of the grate while they are under pressure as this tends to break the kernels and reduce the market value of the product.

A further object oi my invention is to reduce the width of each longitudinal rib of a segment at its Working surface until its upper, or shoulder bearing, edge has substantially the width of the abrading shoulders it bears and thus the Whole face of the rib exposed to the shelling chamber becomes effective as an abrading element. This also enables me to interpose an increased number of ribs bearing shoulders in a grate segment of given size.

Another feature of my invention consists in arranging the bracing Webs, that contact the longitudinal ribs bearing the abrading shoulders, so that they fall out of transverse alignment across the grate, thus making it impossible for any kernel to contact a plurality of these ribs before reaching and making its escape through a hole in the grate. The preferred arrangement is that these webs shall be disposed diagonally to the travel of the nuts.

Another feature of my invention consists in designing the working surface of a grate segment so that its marginal Walls, and particularly its end walls, will themselves carry abrading shoulders so that the abutting end webs of the grate sections shall not present a smooth continuous surface over which nuts might travel Without contact with abrading shoulders.

My invention further comprises the novel details of construction and arrangement of parts which, in their preferred embodiment only, are illustrated in the accompanying drawing which forms a part of this specification, and in which- Fig. 1 is a plan View of one of the cast grate segments.

Fig. 2 is a cross sectional view taken on the line II-II of Fig. 1.

Fig. 3 is a bottom plan view of Fig. 1; and

Fig. 4 is a View broken away of a pair of grate segments abutting end to end and of a modilied design in which abrading shoulders are provided on the working faces of the meeting end Webs of the grate segments.

Fig. 5 is a fragmental View enlarged showing in perspective view a portion of grate segment ribs and illustrating the manner of forming the abrading shoulders thereon.

Similar reference numerals refer to similar parts throughout the drawing.

A grate segment forming the subject matter of my present invention, in its preferred embodiment, is rectangular in shape and transversely curved on an arc corresponding to the curvature of the shelling concave of the machine which is formed by an assemblage of these duplicate grate segments. All this is apparent in the Letters Patent above referred to, and since my invention is conned to the structure of the grate segment per se, it seems unnecessary to illustrate the same here.

My improved grate segment comprises an integral casting having arcuate end walls 6, joined at their ends to side Walls 1, which lie parallel but divergent downwardly since their main body portions lie in planes radial to the long axis of the shelling concave. The end walls 6 are cross connected by parallel longitudinal ribs 8 which taper downwardly from their inner or working faces and are so disposed and. designed that they will have the proper draft to enable the grate pattern to be stripped from a sand mold.

The longitudinal ribs 8, atsuitable intervals throughout their length, are cross braced by connecting webs 9, which webs also taper downwardly and merge into bottom diagonal ribs I0 which at one end join one or the other of the side walls 1 and at the other end preferably terminate short of a junction with the end walls 6, this termination being vdesirable to avoid the provision of large web portions in the grate surface along the end walls which are unneeded there and are objectionable in that they increase the non-working area of the grate surface.

Since the webs 9 follow the diagonal disposition of their bottom ribs I this places them in stepped relation transversely of the grate. Between the webs connecting adjacent ribs 8 I form openings II in the grate which flare outwardly and are of suitable size to permit the shelled kernels to escape freely therethrough. The whole surface of the grate is thus made up of abrasive ribs and holes except for the webs and they are reduced to the minimum size that will adequately lbrace the ribs. Due to the downward are of the openings II, the kernels having once entered them will escape freely through the grate. Each side wall l, along its base, carries an offset flange I2 adapted to form a bottom seat for a side strap or bar I3 (Figs. l and 2) by means of which a series of the grate segments are assembled, end to end, to form a longitudinal sec tion of the grate concave adapted to be mounted and detached as an assembled unit. The bolt holes I., formed in the end walls 'I for the bolts or rivets that connect the bars I3 and grate segments, are so shaped that the cores for forming themwill strip from the sand mold, and this is characteristic of all parts of the grate casting, the same being given throughout the appropriate design that will permit the grate segment pattern to strip vertically from its sand mold.

As seen more clearly in Fig. 2, the ribs 8 rise from a point labove the arcuateunder or convex plane of the grate walls 5 while their upper, or working edges, stand flush with the plane of the arcuate upper or concave edges I5 (Fig. l) of the end walls 6. The working edge of each rib 8 is subdivided by parallel spaced, diagonal grooves I6 (Fig. 5) so as to form in the preferred `manner a series of raised, closely spaced, abrading shoulders II which, as shown, are diamond shaped with their long diagonals disposed at reverse angles on adjacent ribs 8. These grooves IS are cast in the grate segment and produce .a sequence of juxtaposed abrading shoulders I1 occupying Vthe exposed working edge of each rib 8 with their side edges rising from and extending along the side edges of the rib and their end edges lying diagonal to the length of the rib and in overlapping relationship in planes normal to the ribs, so that they will provide abrading edges to lie either normal, and at an angle, to the line of travel of the nuts in the whirl so that the nuts, in passing over each rib 8, will he sure to strike one or more of the abrading shoulders I1 thereon. As will be seen in Fig. 5, the upper surface of the webs 9 lies flush with the bottoms of the grooves It and are thus below the level of the abrading shoulders II. My invention in its broader aspect covers forming such shoulders by welding or otherwise applying them to the ribs.

In Fig. 4 the construction of the grate segments is the same as that above described, with the exception that the upper or concave edge I5 of each end wall 6 is not a continuous face left plain but constitutes a working face which also is provided with grooves or depressions I8 which stand level and in line with the webs 9. The angling grooves IS are continued across these faces I5. The result of this construction is that the rows of albrading shoulders II are continued over the end walls 6 and thus I eliminate any plane surface that extends across the grate surface in the plane of rotation of the whirling nuts therein, and I am enabled to increase the number of abrading shoulders, which constitute the working element of the grate, to the maximum possible.V The diagonal or stepped relation of the webs 9 lis important in that it reduces toa minimumthe non-abrading surfaces within the grate concave that a shelled kernel may contact before reaching a hole II and making its escape.

If the grate were constructed in accordance with design of the patent aforesaid, the webs, corresponding to my elements 9 and I0, that connect and brace the ribs 8 would lie parallel with the end walls 6 of the grate; the working surface or concave edge I5 of each end wall 6 w-ould be left plain and free of any abrading elements, and the shoulders I'I would be seated along the center of the upper or working edge of the ribs f 8 leaving plain surfaces extending substantially on either side of the shoulders thereon. As a result, the number of abrading shoulders that could be effectively provided lupon a grate segment of the old design of a given size was very considerably less than I provide inmy new design of grate, which in addition toits increased Vabrading capacity has also a material increase in the number of openings II that by reason of their size, arrangement and juxtaposition, re-

"- duce to a minimum the possible contact of the shelled kernels with the grate surface. Further, by the application of abrading shoulders I1 along the top edge of the end walls 6, a further elimination of ineifective portions in the shelling concave is accomplished.

In use the nuts are driven in a whirl over the grate in planes normal to the ribs 8 and as the nut shells are centrifugally forced against and over the abrading ribs I'I the latter rapidly grind away the shells until they become so weakened that they burst, free their kernels and the latter will almost immediately pass over and fall into a hole I I so as to escape before becoming broken'.

While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications, without departing from the spirit thereof, `and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or `as are specifically set forth in the appended claims.

What I claim is:

l. As an article of manufacture, a cast concave grate section adapted to form a segment of the shelling concave for peanut shellingv machines and the like, comprising marginal side and end walls forming a frame, spaced parallel ribs connecting the end walls and arranged with their upper edges forming a concave, diamond shaped abrading shoulders defined by grooves extending diagonally from edge to edge across the upper face of said ribs, and webs connecting adjacent ribs and lying below the surface level of said abrading shoulders in parallel rows diagonally across the grate ribs and being reinforced by diagonal bottom brace ribs tied to the frame sides, the Walls, ribs, and webs being relatively disposed and shaped to provide draft for casting the grate section and to form outwardly flaring openings'for the escape of shelled kernels, which openings at their smaller intake Vends are restricted to a size not materially Wider than is requisite for the free escape therethrough of the kernels as soon as shelled.

2. A cast shelling grate segment for peanut shelling machines and the like, comprising a rectangular frame having its working face concave and lying in a curved plane and subdivided by closely associated ribs spaced for the escape of shelled kerns between them and connecting the end walls of the segment, webs ybracing the ribs together, the Webs on opposite sides of `a rib being relatively displaced endwise thereof, and

abrading shoulders disposed along the upper edge' of the ribs said webs lying in diagonal rows running crosswise of the grate and the webs in each row being joined to a bottom tapered rib which depends below the shoulder bearing ribs and is joined at one end to a side frame wall, and said web ribs at the `other end stopping short of a junction with an end frame wall to avoid a blocking off of openings for the escape of kernels adjacent to said end walls.

3. As an article of manufacture, a unitary cast metal grate section for peanut shelling machines. lcomprising a rectangular frame with its side walls cross connected by grinding ribs having narrow, working surfaces spaced just suflciently for the nuts to escape between them, and brace ribs running from the side walls of the frame diagonally across said grinding ribs to brace them together and to said frame and define rows of nut escape openings lying diagonal to the path of the freed nut kernels travel over the grate section, the working surface of said grinding ribs lying'above the upper surface level of said -brace ribs and being cut Iby narrow diagonal grooves into diamond shaped abrading shoulders which except for said grooves occupy the entire working surfaces of said grinding ribs, and yabrading shoulders disposed along the end walls of the grate section in the path of travel of the nuts thereover.

CLARENCE R. MEDLEY. 

